Fratris Crucio
From Warhammer 40k - Lexicanum
The Fratris Crucio were a cadre of torturers and interrogators that formed one of the upper echelons of the Brotherhood of Change. They reported directly to the cult's master, a Chaos Space Marine Sorcerer known as Abasi Amun.[1]
The Crucio were feared throughout the Khandax warzone, to the point that their effect on the morale of the warzone's armies was comparable to that of an Astra Militarum Commissar.[1]